Must/have

Yes.

whatchadoinCan I use both of 'em to express the same idea?

In casual speech you will often hear "both of 'em," but there is no reason at all to use it in writing (unless, of course, you are reporting casual speech). It's distracting, it lowers the "tone" of your writing, and it saves only a single keystroke.

I apologize. I didn't mean to upset you. Sorry.

Aspara GusYes.

So, there's no difference in this case at all?

whatchadoinSo, there's no difference in this case at all?

Not from what I can tell.

I've read that "have to" means "necessity to do something comes from outside" and "must" means "compulsion/necessity comes from you". Is that irrelevant in some cases? Is "must" stronger sometimes?

whatchadoinI've read that "have to" means "necessity to do something comes from outside" and "must" means "compulsion/necessity comes from you".

This is often true, but like almost anything else in English, there are exceptions, namely your example sentences.

whatchadoinIs "must" stronger sometimes?

To my ear, yes.

With "must" the necesity can come from the outside too: You must do as I say. I would say "must" seems more formal to me, but as Aspara Gus has already answered you, there's no real difference in meaning.

whatchadoinI've read that "have to" means "necessity to do something comes from outside" and "must" means "compulsion/necessity comes from you".

This sort of distinction seems to be more prevalent among British writers on the subject. In American English, "have to" is used in virtually all cases of obligation. "must" is almost exclusively reserved for offici

Hi Whatchadoin.Both of these sentences are correct.We use' must 'and 'have to ' to say that it is necessary to do something.Sometimes it doesn't matter which one you use : For ex:Oh,it's later than I thought.I must go or I have to go.
But there is difference between 'must' and 'have to' and sometimes this is necessary or important
'Must' is personal.We use must when we giv